Expansion-mandrel.



M. J. MALOY.

EXPANSION MANDREL.

APPLICATION FILED JUNE 2, 1916.

Patented. July 10, 1917.

' a? .17 fJa 2 10 J Witnesses Attorneys MIcHAEL J. MAtoY, or WOODLAND, MAINE.

EXPANSION-MANDBEL.

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Specification of Letters Patent.

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Application filed June 2, 1916. Serial No. 101,420.

To all whom it may concern:

Be it known that I, hlrcunnn J. ll'l iinov, a

citizen of the United States, residing at WVoodland, in thecounty of WVashington an d State of Maine, have invented a new and useful ExpansionMandrel, of which the following is a specification.

The device forming" the subject matter of this application is an expansion mandrel adapted for holding ring-burs of the S01?! employed in recutting or grinding stones of the kind used for reducing pulp-wood into wood-pulp.

The invention aims to provide novel means whereby the sleeve may be expanded to hold the ring-bur, and to provide novel means whereby the device may be lubricated.

With the above and other objects in view which will appear as the description proceeds, the invention resides in the combina tion and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed can be made within the scope of what is claimed, without departing from the spirit of the invention.

In the accompanying drawings Figure 1 shows in longitudinal section, an expansible mandrel constructed in accord ance with the present invention;

Fig. 2 is a cross section of the device as shown in Fig. 1;

Fig. 3 is a side elevation showing the male expansion element;

Fig. 4 is a side elevation showing the expansible sleeve; and

Fig. 5 is a side elevation showing the female expansion element.

In the accompanying drawings, the numeral 1 indicates a ring bur of the kind used in grinding wood pulp stones. Disposed within the ring bur 1 is a sleeve 2 which is slit longitudinally as indicated at 28, in order that it may be expansib-le. The bore of the sleeve 2 tapers from the ends of the sleeve toward the intermediate portion thereof, as indicated at 3, so that the sleeve is thickest about midway between its ends. In order to facilitate the expansion of the sleeve 2, the same is provided about midway between its ends with longitudinal slits 4 intersected by enlarged openings 5. Owing to the construction above outlined, the sleeve is made yieldable and expansible in its thickest part.

Mounted in one end of the sleeve 2 a male coupling element 6 including a head 7 which is tapered as shown at 8 lo cool'ierate with one of the tapered portions 3 of the bore of the sleeve 2. The head 7 of the male expansion element is provided with a stem 9 terminated in a tapered tip 15. The stem 9 of the male expansion element is circumscribed by threads 10. In one end of the male expansion element 16 are formed one or more oil bores 17, closed at their outer ends with screw plugs 21 or otherwise. The bores 17 open laterally, indicated at 18, into a eircumscribing recess formed in the interior of the male expansion element 6.

The numeral. 19 indicates a female expansion element threaded as shown at 20 to coact with the threads 10 of the male expansion element 6. The female expansion element is externally tapered as shown at 21, to coact with one of the tapered portions 3 of the bore of the sleeve 2. The female expansion element 19 includes an end wall 26 journaled on the tip 15 of the male expansion element 6. In the end wall 26 of the male expansion element, wrench seats 22 are formed.

Disposed within the male expansion ele ment Gand the female expansion element 19 is a bushing 11 which if preferred may be made of brass. The bushing 11 is provided with small perforations 12 connnunicating with the circumscribing internal recess 14 of the male expansion element 6.

Having thus described the invention, what is claimed is 1. In a device of the class described, a sleeve provided at its ends with inwardly tapered bores; a male expansion element including a head, a threaded stem projecting from the head and of less diameter than the stem, the stem having a reduced tip, the head being tapered to cooperate with one bore; and a female expansion element threaded on the stem, the female expansion element being externally tapered to cooperate with the other of said bores, and including the end wall journaled on the tip.

2. In a device of the class described, a sleeve provided at its ends with inwardly t pered bores, the sleeve being provided intermediate its ends with an opening therethrough, there being slots extended longitudinally of the sleeve and prolonged therethrough, the slots communicating with the opening and lying on opposite sides of the opening; and a male expansion element in- In testimony that I claim the foregoing as eluding a head and a threaded stem of less my own, I have hereto aflixed my signature 10 diameter than the head, the head being tain the presence of two Witnesses.

pered to cooperate with one of the bores;

' and a female expansion element threaded on MICHAEL MALOY' the stem, the female expansion element be- Witnesses: ing externally tapered to cooperate With the J. H. MODANIELS, other of the bores. H. P. TOWNSEND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

